American investigates as 777 engine fails to respond to throttle

29 February, 2008

SOURCE: FlightGlobal.com

BY: David Kaminski-Morrow

London

American Airlines is investigating an incident yesterday during which the engine on one of its Boeing 777-200ERs apparently failed to respond to throttle commands for several seconds during approach to Los Angeles.

The incident involved American’s flight AA299 from Miami and occurred at a height of around 2,000ft as the aircraft was descending to Los Angeles.

In an information statement to members, the Allied Pilots Association – which represents American Airlines cockpit crew – says the aircraft experienced a “hang-up” of its left-hand engine.

“The auto-throttles were on and the left engine hung at approach idle as the right engine accelerated normally,” says the association.

“It is believed that the left engine would not respond to throttle inputs for 10-15 seconds before finally responding and accelerating to the commanded thrust.”

All of American’s 777-200ERs are fitted with Rolls-Royce Trent 800 powerplants.

Maintenance personnel have downloaded the flight-data recorder information and will examine the fuel tanks and engine fuel filters for possible contamination. Tests will also be carried out on the electronic engine control.

Neither the US FAA nor the US National Transportation Safety Board has given any further information on the incident. The pilots’ association has not identified the specific aircraft involved. American Airlines could not immediately be reached to confirm the incident.

Investigators in the UK are still trying to determine the reasons why both Trent 800 engines on a British Airways 777-200ER failed to respond to throttle-increase commands during final approach to London Heathrow on 17 January, resulting in the aircraft crashing short of the runway.